(meteorobs) G7IZU meteor alerts improved
yahoo at television.f9.co.uk
Tue Jun 12 15:04:45 EDT 2007
The data source for the G7IZU email alerting system changed at the
beginning of June. The source is now from a receiver tuned to
143.050 MHz. There is a very powerful French "Graves" satellite
radar system operating on that frequency, which is giving very
reliable meteor reflections. The transmitter is so powerful that
it's also giving moon echoes, along with a few large satellites,
although these are not affecting counts much at all.
The other frequencies that I've been using to generate the counts
(48.25 and 60.50 MHz) have become unreliable over the years, and are
basically not good enough to continue accurate meteor counting with.
The Spanish transmitter on 48.25 MHz is particularly bad at the
moment, often drifting off-frequency for long periods. Sporadic-E
conditions also wipe out reception during large parts of the summer
months, and ocal interference is an ever-present problem.
Under "normal" or "flat" meteor conditions, I'm receiving about 100
meteors/hour between 04-07 hrs UT, so no more daily "high alert"
triggers when they're not really needed. So for now, using the new
frequency, the "high" alert trigger is set at 110 meteors/hour,
the "very-high" at 175 meteors/hour.
As the data gets more refined in the coming weeks and months, I'll
program the system to adjust the trigger levels automatically on an
hourly basis, to follow the diurnal cycle, which will then highlight
the daytime meteor showers better too.
The Live FFT output from the new receiver is available at
http://www.tvcomm.co.uk/radio/live_b.html. The original 48/60 MHz
output is still there at http://www.tvcomm.co.uk/radio/live.html.
To subscribe to the meteor alerting service please follow this link:
Any questions, feel free to contact me through the website.
G7IZU Radio Reflection Detection Page
More information about the Meteorobs